line it with jablight (thicker the better up to 100mm its cheap , king span , celotex , recosil good but expensive ) if your aspestos roof is pitched (most are) trioso 10 lath and batten , use pva to stick the jablight , is the aspestos wet underside ? cracked . how old is your concerent floor (membrain) if you can raize the floor and insulate all the better . also insulate the inside of your up and over door if its steel most are